Flyer-head roving pre-twister condenser



March 24,1959 H. M. BACON 2,878,637

FLYER-HEAD ROVING FEE-TWISTER CONDENSER Filed March 18. 1955 HENRY M. BACON INVENTOR.

. United States Patent Office Patented Mar. 24, 1 59 FLYER-HEAD ROVINGPRE-TWISTER CONDENSER Henry M. Bacon, Lacey, Wash. Application March 18,1955, Serial No. 495,283

4 Claims. (Cl. 57-115) My invention relates to roving assemblies and,more particularly, to a flyer-head roving pre-twister condenser.Briefly, the condenser includes an annular body through which the rovingpasses in entering the flyer throat and which produces a false or mocktwist in the free zone of the roving between the nip of the deliverydrawing rollers and the flyer head.

Wool and like fibers in a yarn mill are usually passed through a rovingframe reducing the fibrous rovings and delivering them to a flyer whichlays them on bobbins for further processing. In the drawing rollers ofthe rover, static electricity is generated in the textile fibers. If thefibers are not bound together by twist, moisture or oil, they repel eachother in the free zone when released from the pressure of the drawingrollers. The roving may expand or billow between the delivery rolls andthe flyer. This is a prime cause for loss of weight in the form of lint.The problem of static electricity is increased when artificial orsynthetic fibers are mixed with natural textile fibers. To reduce thistype of loss the mills commonly operate their machinery at such speedsas may not be fully economical.

The use of short staple fibers is common in all textile "yarn,especially in blends with longer fibers. The short 'fibers are prone todrop out unless bound in. The only effective binding is twist.

Therefore, it has been found beneficial to insert a false twist in theroving between the delivery rollers and flyer head. The rotation of theflyer imparts some twist to the roving. The amount of such twist isdetermined, not by the need of the roving coming into the flyer, butrather on what is suitable for the following spinning operation. far toolow for the incoming roving to have suitable twist to safely pass thefree zone. 1

Some work has been done in devices to increase th false twist in thefree zone. densers observed, the twist of the roving is not controlledand does not appreciably condense the roving through 'twist and thecondensers did not permit significant increases in drafting speeds.Further, no condenser observed gave equal twist to front and backflyers, where rovings are handled through different length free zones.

- My condenser appears to be the first that will twist the rovingperfectly between the flyer head and the delivery nip and thus catch andhold lint fibers at the point of delivery.

The objects of my invention include, therefore: to devise an improvedcondenser for a flyer head; to provide condensers particularly adaptedto rovings which are a blend of natural and artificial fibers and oflong and short fibe'rs and those involving trouble with staticelectricity;

to devise a condenser having a continuous and controlled actioncondensing the roving in the free zone back to the delivery rolls; toprovide an improved false twist in the free zone condensing the rovingso as to form firmer, heavier bobbins with a minimum twist on thebobbins;

' toprovide condenser heads particularly adapted for front This twist,proper for spinning, is

However, in those conand back flyers; and to improve the economicoperation of roving frames, including saving fiber and yarns andpermitting greater drafting speeds.

My invention will be best understood, together with additionalobjectives and advantages thereof, from the following description, whenread with reference to the drawings, in which: I

Figure 1 is a fragmentary elevational view showing essential parts of aroving assembly with specific embodiments of my condenser in place;

Figures 2 and 3 are full scale vertical sectional views of twocondensers taken on planes passing through the vertical axes of thecondensers;

Figures 4 and 5 are enlarged perspective views of the condensers withparts broken away'and shown in section; and

Figure 6 is an enlarged, fragmentary elevational view of the front flyerhead with portions of the assembly cut away and shown in section.

In the simplified showing of Figurel a series of drafting rollers 10 areindicated through which front and back rovings 14, 16 are deliveredp Therovings emerge from the nip 12 of the delivery rolls into the free zonebetween the drafting rolls and the flyers. As indicated above, troubleis caused in the free zone due to various factors. The application of anappropriate false twist to the yarn in the free zone will result in lessloss of fiber, the delivery of abetter roving to the flyer resulting inheavier, more compact bobbins, less yarn breakage, and operation of thedrafting assembly at higher speeds. With the use of the front and backcondensers 20, 22 as shown in the drawings, a better false twist hasbeen achieved than has been heretofore possible. A textile mill using mycondensers reports an increase of 20% in the productivity of theirWhitin superdraft rovers. This company reported a marked decrease in rubboard waste, a substantial decrease in fly waste and, also, that thebetter false twist resulted in a decrease of the actual twist on thebobbins so as to obtain a cleaner spin both on Whitin long-draftspinning frames, and on Bradford spinning frames.

Front and back flyer assemblies 24, 26 are of typical construction. Thesimplified showing includes inverted U-shaped flyers 28, 30 dependingfrom hollow flyer heads 32. The hollow arms 40 of the flyers havepivotally supported fingers 44 guiding the yarn in helical wraps orlayers on bobbins 48. It will be understood that conventional means areprovided for rotating the flyers and bobbins, for elevating the bobbinsand for supporting the assembly.

Referring to Figure 6, roving 14 leads into hollow head 32 and outthrough opening 60 into hollow arm 40. The bottom of condensers 20, 22have eounterboi'es 62 which fit the upper ends of hollow flyer heads 32.It is preferred that the condensers be made of resilient material, inwhich case the condensers may be secured in place by a friction ortension fit between condenser and flyer head. If desired, a layer ofadhesive may be interposed to bond the parts together.

Condensers 20, 22 have inverted frusto-conical upper openings, the walls70, 72 of which approximate but do not exceed the angle with thevertical at which rovings 14, 16 enter the flyer heads. To group theparts for illustration purposes, Figure 1 is slightly out of proportionas to the disposition of rovings 14, 16. In an actual installation inwhich the condensers are of the sizes shown in full scale in Figures 2and 3, dimension A in Figure l was 6%", dimension B, 5 /2" and dimensionC, 4%", resulting in a 12" free zone in roving 14 and a 7% free zone inroving 16. In these installations a very slight bend at the topperimeter 74, 76 of conical .the 7%" free zone of roving 16.

It will thus be seen that a dilferent condenser is used for front flyer24 than for the back flyer 26. With the proportions shown and described,the false twist is approximately the same in rovings 14, 16, leading tothe same benefits in condensing the yarn in the free zone and inobtaining compact bobbins. As the flyers wind the yarn on the bobbins,the yarn is straightened from the false twist achieved by condensers 20,22 to a very slight twist which is comparable to that which occurswithout the condensers, but the yarn is denser. This denser yarn on thebobbin means a more efficient spinning operation.

To illustrate the need for different condensers, if condenser 20 is puton the back flyer and condenser 22 on the front flyer, the condenser onthe front flyer more than sufficiently twists the roving 14 so thatexcessive kinking is observed and the condenser on the rear flyerachieves less than sufiicient twist so as to billow the roving 16 backto the delivery rolls and cause fiber loss and roving breakage. Thedimensions above may have to be varied when installations are made inother machines wherein different relationships may exist between theflyer and delivery rolls.

Best results will be obtained when condensers 20, 22 are formed ofresilient material. The rovings may be wet or oily and the material ofthe condensers must be resistant to these agents. Natural or syntheticrubber of 50-70 durometer A hardness has been found suitable for thismaterial. In a practical embodiment currently used of chloroprenepolymer, the rubber hardness test showed 52-54 durometer A. Othermoldable, resilient, oil resistant materials having appropriatecoeflicients of friction are polyethylene, Buna N, Buna S and naturaland reclaimed rubber.

As indicated above, this inexpensive condenser results in verysubstantial saving, both in reduction of lint and in permitting fasteroperation of the rover. Ordinarily, in a well-known rover machine, theflyer-heads rotate at approximately 680 r.p.m. and the delivery rolls oftwoinch diameter rotate at about 118 r.p.m. Through the use of mycondensers the speed of the delivery rolls may be increased to 140r.p.m. which produces approximately a 20% gain in overall production dueto the passage of greater lengths of roving through the rover in anygiven period of time. This startling gain is accomplished withoutincrease in loss of fiber, without reduction in machine efiiciency, andwithout fiber breakage. In addition, the subsequent spinning operationis benefitted. No other condenser observed has comparable constructionand the efiiciency of the structure I have devised has been surprisingand unexpected. From the above it will be understood how the objectivesof my invention have been met.

Primary to achieving these results appear to be the following factors:

(1) Best results will be obtained if the circumferences of the areas ofthe condensers over which the rovings bend, as 74, 76, are directlyrelated to the lengths of the free zones of the associated rovings. Thiswill mean that the longer roving will be subjected to a greater turningaction by the associated condenser. Thus, in the examples given, thelonger roving 14 (having a 12" free zone) is associated with 'a largerdiameter condenser (diameter E is approximately 1.13) and the shorterroving 16 (having a 7 /4" free zone) is associated with a 4 smallerdiameter condenser (diameter E is approximately 0.9").

(2) However, the twisting action imparted to the rovings is alsodependent on the angle of the bend of the rovings over the condenser. Inthe examples given herein, roving 14 approaches condenser 20 at an angleof 58 degrees with the vertical and the conical wall 70 is approximately49 degrees from the vertical resulting in a bend in roving 14 of about 9degrees. Roving 16 approaches condenser 22 at an angle of approximately37 degrees with the vertical and conical wall 72 approximately 23degrees from the vertical, resulting in a bend in roving 16 of about 14degrees. As stated before, if condenser 22 is placed on the front flyerhead, this results in excessive twist when the roving is bent about 35degrees. This demonstrates that the circumference of the condenser isnot totally responsible for the twisting action because a greater twistwas achieved although the smaller diameter condenser 22 was placed onthe'front flyer head. Yet the diameter of the condenser will beunderstood to aflect the amount of twisting action imparted. If acondenser is used having approximately the same diameter as the flyerhead, the results described above will not be achieved, e. g., the speedof drafting cannot be substantially increased and the yarn will not havea comparable false twist. The diameter of areas 74, 76 should be atleast double the diameter of the interior of hollow flyer head 32. Forthe purpose of some of the claims, it is stated that the roving bendsover the condenser at least five degrees and not more than 25 degrees.This range is operative and best results will be achieved closer to theexamples given of nine and fourteen degrees.

(3) The condensers should be formed of rubber-like material of thespecified durometer hardness or another material having an equivalentfriction, i. e., a knurled surface of the same hardness or with anabrasive additive will have a greater turning action on the yarn than aplane surface.

(4) The interior walls 70, 72 should not form a lesser angle with thevertical than the associated rovings so as not to interfere with thebending action of the condenser on the rovings.

Having thus described my invention, I wish to cover those variations indesign which will occur to those skilled in the art and which are withinthe scope of the invention disclosed herein, as defined in the appendedclaims.

I claim:

1. The improvement in a roving assembly in which a pair of textile fiberrovings lead from the nips of delivery drafting rollers of a rovingframe to the rotating hollow heads of a front and a back flyer,comprising: an annular condenser of resilient material mounted on eachflyer head having an upper central opening through which the associatedroving passes into the flyer head, the wall of the central opening fromthe top of the flyer head to adjacent the top of the condenser being ofinverted unbroken frusto-conical shape tangential with a more widelyflaring curved edge, the angle of each roving with the vertical beingdifferent and being at least five and not more than twenty-five degreesgreater than the angle with the vertical of the conical wall of theassociated condenser, whereby the roving is bent over the upper marginof the conical wall, the circumference of each conical wall in the planeof the bend of the associated roving being different with the rovinghaving the longest free zone between delivery rollers and flyer headrequiring a condenser of larger circumference and both circumferencesbeing at least double the circumference of the interior of the flyerhead.

2. The improvement in a roving assembly in which a textile fiber rovingleads from the nip of delivery drafting rollers of a roving frame to therotating hollow head of a flyer, comprising: an annular condenser ofresilient material mounted on said flyer head having an upper centralopening through which the roving passes into the flyer head, the wall ofthe central opening from the top of the flyer head to adjacent the topof the condenser being of inverted unbroken frusto-conical shape tangential with a more widely flaring curved edge, the angle of the rovingwith the vertical being at least five and not more than twenty-fivedegrees greater than the angle with the vertical of the conical wall,whereby the roving is bent over the upper margin of the conical wall,the circumference of the conical wall in the plane of the bend of theroving being at least double the circumference of the interior of saidhollow flyer head.

3. The improvement in a roving assembly in which a pair of textile fiberrovings lead from the nips of delivery drafting rollers of a rovingframe to the rotating hollow heads of a front and a back flyer,comprising: an annular condenser of resilient material mounted on eachflyer head having an upper central opening through which the associatedroving passes into the flyer head, each central opening having anannular, unbroken upwardly-flaring wall over which the associated rovingis bent at a substantial angle, the circumference of eachupwardly-flaring wall in the plane of the bend of the associated rovingbeing different with the roving having the longest free zone betweendelivery rollers and flyer head requiring the larger circumference.

4. The improvement in a roving assembly in which a textile fiber rovingleads from the nip of delivery drafting rollers of a roving frame to theconventional rotating hollow head of a flyer, comprising: an annularcondenser of resilient material mounted on said flyer head having anupper central opening through which the roving passes into the flyerhead, the central opening having an annular unbroken upwardly-flaringwall over which the associated roving is bent at a substantial angle,the circumference of the upwardly-flaring wall in the plane of the bendof the roving being at least double the circumference of the interior ofsaid hollow flyer head.

References Cited in the file of this patent UNITED STATES PATENTS2,702,982 Guyot Mar. 1, 1955 FOREIGN PATENTS 3,820 Great Britain of 1887440,546 Italy Oct. 13, 1948 1,062,236 France Dec. 2, 1953

